The present application is based on and claims priority from Japanese Patent Application No. Hei 10-72493 filed on Mar. 10, 1998, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a wiper blade of a wiper device for wiping a vehicle windshield.
2. Description of the Related Art
A wiper blade of a vehicle wiper device is usually a tournament-graph-type that is effective to wipe a curved windshield. Such a tournament-graph-type wiper blade is composed of a primary lever, a plurality of secondary levers, a plurality of yoke levers and a rubber blade. The primary lever supports the plurality of secondary levers, which supports the plurality of yoke levers. The plurality of yoke levers finally support the rubber blade. In other words, the levers are swingably stacked one on another in the direction perpendicular to the windshield or in the height of the windshield.
Such a tournament-graph-type wiper blade has to increase the number of levers if it has to wipe a curved windshield having a higher curvature. This increases the number of related parts and manufacturing steps, thereby resulting in high cost.
As the number of the levers increase, dynamic lift also increase due to increase of projected area thereof to the cross-section of air flow flowing along the windshield while a vehicle is running. Therefore, a wiper device has to have a strong spring and arm members to prevent the wiper blade from lifting, thereby resulting in high cost.
JP-A-4-129862 proposes a modified tournament-graph-type wiper blade in which respective levers are disposed on the opposite sides of the rubber blade to support the same. Although this structure is effective to reduce the projected area stated above, manufacturing cost necessarily increases if this structure is applied to a windshield having a high curvature because of the tournament-graph-type structure.
A main object of the present invention is to provide a simple wiper blade having a nice-looking spoiler which can wipe a curved windshield of a high curvature.
According to a main aspect of the invention, a wiper blade including a first lever having a first spoiler extending in longitudinally opposite directions along a side of a rubber blade, a pair of second levers connected to the first spoiler and having a second spoiler extending in line with the first spoiler, a pair of third levers connected to the pair of second spoilers.
Another object of the invention is to provide a wiper blade that can operate even in very cold and freezing conditions.
For this object, the above wiper blade may have a plurality of sealed connecting portions disposed between the first spoiler and each of the pair of second levers and between each of the pair of second spoilers and one of said third levers.